• Journal of the Korean Home Economics Association
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• v.24 no.3
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• pp.59-67
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• 1986

The heat of sewing needle is generated through the friction during the needle penetration into and withdrawal from fabrics. Therefore, effects of sewing condition for knitted fabric on the heat generation of needle was examined. The needle size was not the large influence factor of heat generation of needle but the needle point shape significantly affects needle temperature. And the super needle coated with fluoro resin had more effect on reducing the heat of needle. The decrease of sewing speed and the increase of stitch rate had more effect on the reduction in needle temperature. Also the Influence of a sewing thread on the needle temperature was very large compared with bare needle. As expected, an increase in the number of fabric layers result in higher needle temperature.

• Journal of applied mathematics & informatics
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• v.9 no.2
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• pp.731-744
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• 2002

The temperature distribution in human skin and subdermal tissue layer is presented using bioheat transfer equation. The body temperature is determined by the balance between heat produced and heat lost by our body. The time-dependent solutions have been found to be affected by the metabolic heat generation rate, blood mass flow, the rate of evaporation of perspiration and also by the atmospheric temperature. The analytic solutions for different layers have been calculated numerically and are also shown graphically.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.1
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• pp.7-14
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• 2017

This study carried out a numerical analysis of the effects of hot waste water supply on the performance of a Type II absorption heat pump. There are two types of hot waste water supply, regular series flow and reverse series flow. Also it investigated the interaction between each type of flow and heat exchange solutions. As the effectiveness of heat exchange solutions increase, the steam generation and (COP) increase as well. If the effectiveness of a heat exchange solution is lower than 0.566, the steam generation rate of the reverse flow is lower than that of the regular series flow. A high effectiveness of heat exchange solution is therefore required to make a larger amount of steam in reverse series flow than with ordinary series flow. The COP difference between the two types of flow decreases with the increasing effectiveness of the heat exchange solution. Thus, a reverse flow type absorption heat pump can match the high steam generation rate and COP of the ordinary flow type when a highly effective heat exchange solution is applied.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.210-215
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• 2002

In respect of global environment protection and efficient utilization of energy, co-generation systems, which have greatly higher efficiency than the other generations, have been developed and put to practical use. Assuming that the co-generation system would be operating in Park Hotel, this paper calculates the difference between the heat and electricity rates by the conventional method and the co-generation system, considers the cost of new investment and analyzes introduction economics based on the return on investment. The introduction is turned out to be recommendable, since the return of investment for co-gen oration equipment is about ten years when the co-generation profits in heat and electricity rate. Additionally, accounting for interest rate drop, improvement of environmental matters or electricity rate increase, it is shown to be even more economical.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.84-90
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• 2016

Various form of membrane structures are being built in recent years. However, there is no appropriate fire proofing standards which can be applied each specific membrane structures. Therefore, existing fire protection standards are in establishment state and they need to be revised. In the current study, commonly used membrane materials(ETFE, PVF, PTFE) has been selected to investigate its fire resistance behavior with the change of fire duration time. In addition to this, heat generation rate of the membrane materials in correlation with the height of membrane has been investigated. And these fire combustion characteristics of membrane materials can be used in future practice for the fire prevention regulations of membrane structures.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.389-395
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• 2018

The present work aims to report the consequences of Darcy-Forchheimer medium in flow of Cross fluid model toward a stretched surface. Flow in porous space is categorized by Darcy-Forchheimer medium. Further heat transfer characteristics are examined via thermal radiation and heat generation/absorption. Transformation procedure is used. The arising system of nonlinear ordinary differential equations is solved numerically by means of shooting method. The effects of different flow variables on velocity, temperature, concentration, skin friction, and heat transfer rate are discussed. The obtained outcomes show that velocity was enhanced with the increase in the Weissenberg number but decays with increase in the porosity parameter and Hartman number. Temperature field is boosted by thermal radiation and heat generation; however, it decays with the increase in the Prandtl number.

• Korean Journal of Metals and Materials
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• v.48 no.4
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• pp.277-288
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• 2010

The hot corrosion properties of heat-resistant steels were investigated in an oxidation atmosphere including artificial ash and sulfur dioxide. The heat-resistant steels of T22, T92, T122, T347HFG, Super304H and HR3C were evaluated at 620, 670 and $720^{\circ}C$ for 400 hours. The relationship between the corrosion rate and the temperature followed a bell-shaped curve with a peak rate at around $670^{\circ}C$. The corrosion rates showed a decreasing tendency as the chrome contents of these steels increased from 2.15 wt.% to 24.5 wt.%, and austenitic steels had a lower corrosion rate than ferritic steels. Sulfidation by $SO_2$ as well as molten salt corrosion also had an effect on the total corrosion rate, especially showing an increase in the corrosion rate in ferritic steels. Regardless of the chrome content in the steels and irrespective of the test temperature, the corrosion scale was composed of an outer oxide and an artificial ash mixed layer, a middle oxide layer and inner sulfide, and a mixed oxide layer. As the chrome content increased, the proportion of chrome oxide in the corrosion scale increased. Before spalling of the corrosion scale, voids and cracks were initiated in the sulfide and the mixed oxide layer or at the interface with the substrate.

• Fire Science and Engineering
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• v.34 no.2
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• pp.1-6
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• 2020

The energy released by various burning material has a wide range of its magnitude and transient characteristics, the measurement of the heat release rate(HRR) has been considered as one of the most challenging issue among the parameters related to fire. This study compares the measured HRR calculated by the oxygen consumption (OC) method and the carbon dioxide generation (CDG) method using a laboratory-scale fire calorimeter. The feasibility of the CDG method is examined by analyzing the relative error. The relationship between the oxygen depletion factor and CO₂ mass flow rate, which is a key parameter in HRR calculations, showed strong linearity at 6 % for the methane burner fire. The contribution of HRR by CO was less than 7% compared with the of HRR by CO₂ in the CDG calculation method. The linearity of the OC and CDG methods with respect to HRR of the referenced methane burner in a quasi-steady state was less than 1%; this indicates that the CDG method can be utilized as a complementary method in heat release rate measurement.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.181-184
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• 2000

The cooling rate of a bioreactor was measured to estimate the heat generation by microbial cultivation production. The estimated heat production was calculated from the varying temperature of cooling water. It was used for monitoring growth and specific metabolic events for microbial cultivations. Metabolic heat measured was also adopted for a control parameter for fed-batch cultivation.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.144-149
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• 2006

In this study ice making characteristics are experimentally investigated for the ice slurry generating system which is pneumatically operated. The experimentations are conducted under the various test conditions such as chilled water inlet temperature, aqueous solution concentration, flow rate of cooling water, scraper pitch and frequency of cylinder stroke. For the above experimental conditions, ice making characteristics of the slurry ice generating system are evaluated in terms of the overall heat transfer coefficient, heat transfer rate and the amount of slurry ice generation. And the experimental results show that the heat transfer rate of the system increases as the flow rate of cooling water solution increases and the concentration of ethylene glycol and inlet temperature of chilled water decreases.